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Re: Si pin xrf ..1st go
¿ªÔÆÌåÓýLOD depends on the element but in general the XRF limit of detection at best is 0.5 ppm and above, so for a ppb range element you¡¯ll need to do ICP/MS. That can also get stable element isotopic ratios of end member decays for forensics. Dud ? From: [email protected]
[mailto:[email protected]] On Behalf Of GEOelectronics@...
Sent: Monday, September 28, 2020 11:39 AM To: [email protected] Subject: Re: [XRF] Si pin xrf ..1st go ? Dud, with the XRF gun, what is the likelihood of detecting a unique element in a large Trinitite sample, when the element dispersed and total weight is 1x10e-9 grams? Say the sample was 28 grams. ? Geo ? From:
"DFEMER"
<dfemer@...> ? The same scale expansion can be done selecting the Select View box on the tool bar. The cursor changes to a + and by holding the left mouse button you can select the range to expand. Click the? < > button and it expands back to full scale. Unclick the Selec View Box to get back to the Arrow pointer for selecting peak readouts Dud. ? From: [email protected] [mailto:[email protected]] On Behalf Of GEOelectronics@... ? Your sensor box and RAPCAP (AmX6 ring) are in good geometry. The case of the GEO-1-2-3 is also a heat sink so make sure there is airflow around it.No blower needed, just natural air. The case gets warm like a puppy, not hot. ? ? ? Try this-The 1-2-3 does not have to be connected or turned on for this: ? On your selenium scan- ? ? Bring up the saved .mca file by using FILE; OPEN FILE function. If no other files are loaded, it will appear as Live_Data2. ? ? Press F6 to show SPECTRA LIST drop down (if it is not on the screen already). Click on? title Live_Data2, there will be a drop down menu, one of the options is MODIFY- select that. Within the page that comes up, you can rename the scan, maybe Se-1_Septxx2020 ? ? ? ? When that's done ,select the selenium scan, and change one setting on that- in the RANGE boxes at the bottom change the first box from 0 to 3 and the second one change from 133 to 62. ? This will eliminate the noise at the bottom (far left) and spread out the data more and give much more detail on the screen. This is the main useful range of Si-PIN sensors. I include 62 in all my scans to preserve 59.5 as a calibration point. ? Later you will want to examine even smaller groups of? peaks, so you can then change the RANGE boxes to say maybe 2 and 25 or whatever range contains the details you want to investigate at that moment. ? ? By the way for all members using this same device, my recent posts on Trinitite were made with one, notice some scans are from January-February 2020 and some are from Sept2020. These are all made with same sensor s/n and still use same calibration factors after being turned off for 6+ month! No drift.? ? have fun Geo From:
"taray
singh via groups.io" <sukhjez@...> ? Hi guys Using 6 Am241 /ludlum??lead disc??glued to cardboard box Si pin??near orifice Due to the shape of detector and fear of samples potentially damaging Be window,I opted for this way Anyway it is only a prototype. Accidentally glued one the Am buttons upside down and it is really stuck Will fix it next time.. Samples as follows? 1 Selenium Was discussed in the old forum My sample is a centrifuged suspension of selenium sulphide(selsen) in a??plastic sample container .It has remained the same since preparation about 2 years ago It sticks like a coating so without a container,alpha is active. ? 2 X ray apron polymer Nowadays they are lead free and consist of polymers mixed??with antimony,tungsten or bismuth etc to make it light weight? I always thought there was antimony present in my sample from my previous xrf experiments.It appears to Tin here?? 3 Bipp a bismuth iodine medical paste ? 4 Mn 99.7% purity in a plastic container? ? Thanks Taray ? ? |